Ok , i just ordered this lens for a very sharp price , it's the replacement for my kit lens.
I hesitated with the Pentax 16-50mm f/2.8 which costs almost 3 times more but after reading so many bad reviews of the Pentax i decided to play it safe

Only reason I can think of to choose the Pentax over the Tamron is for the weather sealing. Otherwise, the Tamron is a very good choice. Eventually I'll probably buy the Pentax as I really want the weather sealing. I have other choices now for this focal length.

Only reason I can think of to choose the Pentax over the Tamron is for the weather sealing. Otherwise, the Tamron is a very good choice. Eventually I'll probably buy the Pentax as I really want the weather sealing. I have other choices now for this focal length.

Before buying the Pentax do go see what the forum reviews say about it , it's not bright at all , this lens looks good at the center but borders are extremely bad , and seems that at almost all focals below f/5.6 the Tamron is one of the best of all standard lenses and the Pentax by far the worse

What's the point of buying a bright f/2.8 lens if you need to shoot at f/5.6 and more for good results

I temporarily had 2 of the Pentax DA*16-50. The first one was obviously defective with significant decentering. The second one was really sharp at f2.8, the color was wonderful and I was really tempted to keep it and send it in for repair. I think it had been damaged in shipment (the outer box was crushed on one side) - the zoom ring was very stiff. But I ended up returning it for a refund. So based on my experience, there's a huge variance between copies and I just wish my first copy had been as good as the second one was optically - the first one was otherwise fine.

The Tamron does me no good if I'm hiking in snow and rain, or shooting in high winds in the desert where blowing sand/dust is a problem. At all other times I can use the DA 12-24 (granted, it's not as bright) and DA 35 macro (which is as bright) so neither lens (Pentax or Tamron) gives me any real advantage.

I got Tamron few days ago and I must say it's excellent. Very sharp in centre even at f2.8 (if you can get focus right). On my ist DL2 it has slight problem focusing but I have split focusing screen so I can correct it without too much trouble. Stopped down to f4 it's just great, going over f8 it begins to get softer. I'll post some photos in main Pentax forum.

is that standard for that lens to have such problems? it looks liek its making quite a difference, It looks like a great lens but if the AF is that horrid, Id be more inclined to drop a quarter of the cost on an older MF lens. (Then again older man focus lenses tend to not have anything wider than 24 at wide)

Do u think its a bad copy? I ask because Ive been considering that lens down road, but now im reconsidering

is that standard for that lens to have such problems? it looks liek its making quite a difference, It looks like a great lens but if the AF is that horrid, Id be more inclined to drop a quarter of the cost on an older MF lens. (Then again older man focus lenses tend to not have anything wider than 24 at wide)

Do u think its a bad copy? I ask because Ive been considering that lens down road, but now im reconsidering

From what I could see on my photos it could be my fault. Some portraits I did were pin sharp at f2.8 some were back and some front focused. With such a shallow DOF it's really hard to tell. Also it could be that my camera selected some stupid focusing point (DL2 doesn't show which one it's using). You'd have to do a proper test, but at 50mm with f3.5 I have a very sharp photo where the eyes are sharp but ears are blurred.
I'll try to find some time to take some more photos at f2.8 and see how they come out.